As is well-known in the art, thermophysical properties of underground formation fluids (e.g., hydrocarbons) vary with pressure, temperature and chemical composition. The thermophysical properties of interest to the petroleum industry include, but are not limited to, viscosity, density, thermal conductivity, heat capacity and mass diffusion. These properties at least partially govern the transport of hydrocarbons in the underground formation, and consequently, the recovery processes of the formation fluid from the formation. Thus, it is desirable to characterize formation fluid at a plurality of pressures and/or temperatures for zones within reservoirs.
Currently, this characterization may be carried out on fluid samples captured by a downhole sampling tool lowered in a wellbore and brought back to the surface. This characterization is often commonly referred to as PVT laboratory analysis. However, the surface analysis may have several limitations. In particular, as the fluid sample is brought back to the surface, the sample may undergo physical transformation (e.g., phase transitions) and some components (e.g., gases) may escape the sample. Thus, the PVT laboratory analysis may lead to approximate results. Moreover, the PVT laboratory analysis results are available once the sampling tool has been retrieved to the surface. However, these results may be used to advantage when the sampling tool is still in the wellbore, for example to design and execute subsequent sampling operations. Retrieving the sampling tool from the wellbore, analyzing the captured samples and lowering again a sampling tool in the wellbore delays the acquisition of critical information about the underground formation fluid and increases the cost of characterizing the underground formation fluid. Furthermore, the number of samples that can be brought to and analyzed at the surface is limited, and therefore the sampling tool may have to be lowered several times in the wellbore.